THROMBOSED BRAINSTEM DEVELOPMENTAL VENOUS ANOMALY CAUSING HYDROCEPHALUS

Developmental venous anomaly (DVA) is a commonly encountered congenital abnormality of the venous drainage system. Spontaneous thrombosis of DVA is rare. We present a case of thrombosed brainstem DVA leading to venous infarction and oedema within the posterior fossa. A 49 year old, previously fit gentleman presented to the local hospital with a one day history of headache, slurred speech and incoordination. Examination demonstrated GCS of 13/15, cerebellar dysarthria, horizontal nystagmus to the left, mild right sided pyramidal weakness, right sided cerebellar ataxia and bilateral extensor plantars. CT venogram revealed a cerebellar DVA with thrombosis of one of the veins. There was surrounding venous infarction and oedema within the posterior fossa, causing compression of the fourth ventricle and dilatation of the lateral ventricles. MRI demonstrated extensive T2 change in the right cerebellar hemisphere, dorsal pons and right cerebral peduncle. No underlying thrombotic tendency was identified. He was treated successfully with intravenous heparin infusion. He improved over the next 3 weeks, and was discharged on warfarin with mild right sided ataxia and cerebellar dysarthria. Our case demonstrates that DVAs, generally considered as common insignificant anatomical variants, can uncommonly lead to significant complications.